logic: added Gradle project setup (issue #379)

* added implementation for Gradle project setup (icon is still missing)
* refactored project loading/saving and SourceGroupSettings
* removed long deprecated Cxx UseSourcePathsForHeaderSearch option

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java_indexer/pom.xml

@@ -24,11 +24,37 @@
 		</plugins>
     </build>
 	
+	<repositories>
+		<repository>
+			<id>mvnrepository</id>
+			<name>mvnrepository</name>
+			<url>http://www.mvnrepository.com</url>
+		</repository>
+		<repository>
+			<id>repo_gradle</id>
+			<name>repo_gradle</name>
+			<url>http://repo.gradle.org/gradle/libs-releases-local</url>
+		</repository>
+	</repositories>
+	
 	<dependencies>
 		<dependency>
 			<groupId>org.eclipse.jdt</groupId>
 			<artifactId>org.eclipse.jdt.core</artifactId>
 			<version>3.12.3</version>
 		</dependency>
+		
+		<dependency>
+			<groupId>org.gradle</groupId>
+			<artifactId>gradle-tooling-api</artifactId>
+			<version>4.2</version>
+		</dependency>
+		
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-simple</artifactId>
+			<version>1.7.10</version>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 </project>

java_indexer/src/main/java/com/sourcetrail/gradle/InfoRetriever.java

@@ -0,0 +1,133 @@
+package com.sourcetrail.gradle;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintStream;
+import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.gradle.tooling.BuildLauncher;
+import org.gradle.tooling.GradleConnector;
+import org.gradle.tooling.ProjectConnection;
+
+public class InfoRetriever 
+{
+	public static String getMainSrcDirs(String projectRootPath, String initScriptPath)
+	{
+		String ret = "";
+		
+		List<String> srcDirs = getSrcDirs("printMainSrcDirs", projectRootPath, initScriptPath);
+		for (int i = 0; i < srcDirs.size(); i++)
+		{
+			if (i != 0)
+			{
+				ret += ";";
+			}
+			ret += srcDirs.get(i);
+		}
+		
+		return ret;
+	}
+	
+	public static String getTestSrcDirs(String projectRootPath, String initScriptPath)
+	{
+		String ret = "";
+
+		List<String> srcDirs = getSrcDirs("printTestSrcDirs", projectRootPath, initScriptPath);
+		for (int i = 0; i < srcDirs.size(); i++)
+		{
+			if (i != 0)
+			{
+				ret += ";";
+			}
+			ret += srcDirs.get(i);
+		}
+		
+		return ret;
+	}
+	
+	public static void copyCompileLibs(String projectRootPath, String initScriptPath, String targetPath)
+	{
+		executeTask("copyCompileLibs", projectRootPath, initScriptPath, Arrays.asList("-Psourcetrail_lib_path=" + targetPath));
+	}
+	
+	public static void copyTestCompileLibs(String projectRootPath, String initScriptPath, String targetPath)
+	{
+		executeTask("copyTestCompileLibs", projectRootPath, initScriptPath, Arrays.asList("-Psourcetrail_lib_path=" + targetPath));
+	}
+	
+	private static List<String> getSrcDirs(String taskName, String projectRootPath, String initScriptPath)
+	{		
+		String output = executeTask(taskName, projectRootPath, initScriptPath, null);
+		
+		List<String> paths = new ArrayList<>();
+		
+		try (BufferedReader reader = new BufferedReader(new StringReader(output))) 
+		{
+		    String line;
+		    while ((line = reader.readLine()) != null)
+		    {
+		    	paths.add(line);
+		    }
+		} 
+		catch (IOException e) 
+		{
+			// TODO: LOGERROR
+		}
+		
+		return paths;
+	}
+	
+	private static String executeTask(String taskName, String projectRootPath, String initScriptPath, List<String> additionalArguments)
+	{		
+		ProjectConnection connection = GradleConnector
+				.newConnector()
+				.forProjectDirectory(new File(projectRootPath))
+				.connect();
+		
+		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+		ByteArrayOutputStream errorStream = new ByteArrayOutputStream();
+		
+		try 
+		{
+			List<String> arguments = new ArrayList<>();
+			arguments.add("--init-script");
+			arguments.add(initScriptPath);
+//			arguments.add("-q");
+
+			if (additionalArguments != null)
+			{
+				arguments.addAll(additionalArguments);
+			}
+			
+			BuildLauncher Launcher = connection.newBuild().forTasks(taskName)
+					.withArguments(arguments)
+					.setStandardOutput(new PrintStream(outputStream))
+					.setStandardError(new PrintStream(errorStream));
+			
+			Launcher.run();
+		} 
+		catch (Exception e)
+		{
+			// TODO: LOGERROR
+		}
+		finally 
+		{
+			connection.close();
+		}
+		
+		if (!errorStream.toString().isEmpty())
+		{
+			// TODO: handle this by sending the error to cpp
+		    System.out.println("Error: " + errorStream.toString()); // TODO: remove this later
+		}
+		
+		return outputStream.toString();
+	}
+}